JP5325481B2 - Measuring method of optical element and manufacturing method of optical element - Google Patents

Description

  The present invention relates to an optical element measuring method and an optical element manufacturing method for measuring defects of an optical element using a lens measuring machine that measures an optical surface shape, a center thickness, an eccentricity, and the like in the optical element.

As a lens measuring machine (or a lens inspection machine) for measuring the optical performance of an optical element such as a lens, for example, a technique described in Patent Document 1 related to the application of the present applicant is known.
In Patent Document 1, a light beam from a light source is divided into two optical paths, a reference lens as a comparison target is arranged in one optical path, a test lens as a measurement target is arranged in the other optical path, and a reference lens A technique is disclosed in which an optical fringe is generated by again synthesizing the luminous flux transmitted through the lens and the luminous flux transmitted through the test lens, and the optical performance is measured by calculating the aberration amount of the test lens from the interference fringe.
Japanese Patent No. 3206984

  However, in Patent Document 1, the transmitted wavefront is measured by transmitting the light beam through the lens on the basis of the optical surface (optical function surface). However, in such a lens measuring machine, the light beam is transmitted through the optical surface. Although the optical surface is visible, the defect of the optical surface of the lens could not be measured.

  That is, the lens measuring machine of Patent Document 1 can inspect optical performance including all information, but measures the presence or absence of internal defects such as scratches, blisters, spiders, foreign matter adhesion, bubbles, etc. on the optical surface. It does not have a function to do. For this reason, conventionally, it has been necessary to measure lens defects with a dedicated visual inspection machine.

In addition, in this case, it has been necessary to transfer the lens to be inspected from the lens measuring machine to the appearance inspecting machine, and it is necessary to set the lens to be tested each time.
Therefore, it would be convenient if the optical performance of the lens to be tested and the presence or absence of defects could be measured simultaneously using a single device, thereby reducing the number of measurement steps.

  The present invention has been made to solve such a problem, and provides an optical element measuring method and an optical element manufacturing method capable of simultaneously measuring a transmitted wavefront of an optical element and measuring a defect. Objective.

In order to achieve the above object, an invention of an optical element measuring method according to claim 1 comprises:
On the apparatus for measuring the aberration amount of the test lens from the generated interference fringes by causing the light beam transmitted through the reference lens as the comparison target to interfere with the light beam transmitted through the test lens as the measurement target. By measuring these defects, it is possible to perform pass / fail determination including lens defect measurement without moving between a plurality of measuring instruments.

The invention according to claim 1 further includes
Of course, the measurement of the defect of the test lens can be evaluated on the same measuring instrument by performing the same measurement posture of the test lens at the time of transmission wavefront measurement for measuring the aberration amount. It is characterized in that it is not necessary to change the lens attitude setting when measuring defects.

The invention according to claim 1 further includes
The measurement of the defect of the test lens is performed without causing interference between the light beam transmitted through the reference lens and the light beam transmitted through the test lens, and evaluation is performed in a state where noise at the time of defect measurement is eliminated. .
The invention according to claim 1 further includes
The measurement of the defect of the lens to be examined is performed by changing the setting of the optical system from the lens to be projected to the projection surface and the photographing system, and the observation state is usually not required by the interference fringe projection optical system. The imaging optical system has a lens surface (object point) as a target.
The invention according to claim 1 further includes
The measurement of the defect of the test lens is performed by adding a stop to the observation optical system, changing the principal point and F number of the optical system, changing the object point (observation target surface), and changing the object according to the size of the stop. It is characterized by adjusting the depth of field.

The invention according to claim 2 is the method of measuring an optical element according to claim 1 ,
The measurement of the defect of the lens to be measured is performed without generating an interference fringe by shielding the light beam transmitted through the reference lens.

The invention according to claim 3 is the optical element measurement method according to claim 1,
A light beam suitable for measuring the defect of the lens to be measured is selected, and the light beam different from the measurement of the aberration amount is irradiated to the lens to be tested.

The invention according to claim 4 is the optical element measurement method according to claim 3 ,
A light beam incident angle and a light beam state suitable for measurement of a defect of the lens to be examined are selected, and a light beam different from the measurement of the aberration amount is irradiated from a direction different from the optical axis.

The invention according to claim 5 is the optical element measurement method according to claim 3 or 4 ,
The measurement of the defect of the lens to be measured is performed by irradiating a light beam different from the measurement of the aberration amount from both surfaces of the lens to be tested, so that the defect measurement on both surfaces can be performed simultaneously. .

The invention according to claim 6 is the optical element measurement method according to claim 1 or 3 ,
By measuring the defect of the test lens by rotating the test lens, the measurement can be performed a plurality of times from a plurality of directions.

The invention according to claim 7 is the optical element measurement method according to claim 1 or 3 ,
The measurement of the defect of the test lens is performed by rotating the test lens, and a plurality of images obtained are evaluated to ghost or flare that may be generated by the defect measurement light beam. It is characterized in that a defect measurement result is obtained in a state in which is removed.

The method for manufacturing an optical element according to claim 8 comprises:
A molding process for molding a lens to be measured as a measurement object;
A defect in the test lens is detected on an apparatus for measuring the amount of aberration of the test lens from interference fringes generated by causing the light beam transmitted through the reference lens as a comparison target to interfere with the light beam transmitted through the test lens. a measurement step of claim 1 to 7 to be measured,
Whether to continue the molding of the test lens based on the measurement result in the measurement process, or a step of feeding back to the molding process the timing of performing maintenance of the mold and molding apparatus used for molding, It is characterized by providing.

  According to the present invention, it is possible to simultaneously measure the transmitted wavefront of the optical element and the defect of the optical functional surface with one apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing the overall configuration of a lens measuring instrument 1 (lens comprehensive inspection machine) used in the method of the present invention.

  This lens measuring machine 1 is a combination of an interferometer 4 and a fringe analysis apparatus 5 (image processing PC) for analyzing interference fringes. This interferometer 4 measures the phase shift of the light based on the optical path difference between the optical paths R and S divided into two by the beam splitter 16 by using a Mach-Zehnder interferometer that captures the movement of the interference fringes. Yes.

  The interferometer 4 allows the light from the laser 11 to pass through the variable ND filter 43, expands its diameter by the beam expander 12, divides the light into two optical paths R and S by the beam splitter 16 through the aperture stop 15, and separates them. These optical paths are combined again by the beam splitter 24 to project interference fringes on the screen 10.

  On the two optical paths R and S divided by the beam splitter 16 of the interferometer 4, a reference lens 6 as a comparison target and a test lens 7 as a measurement target are arranged. In this embodiment, it is assumed that the reference lens 6 and the test lens 7 are concave lenses.

  When an aspherical lens whose needs have been increasing in recent years is a lens to be measured, a lens close to a design value is found as a reference lens 6 from among several test lenses 7 by a conventional method or the like. Alternatively, a precision aspheric lens close to the design value may be made by precision grinding or the like and used as the reference lens 6.

Since the two optical paths R and S are made completely equivalent, the optical path length difference of the test lens 7 with respect to the reference lens 6 is projected on the screen 10 as interference fringes.
As a result, assuming that the reference lens 6 is a lens according to a desired design value, the projected interference fringes represent the wavefront aberration of the test lens 7. By analyzing the wavefront aberration obtained from the interference fringes, it is possible to grasp changes in items affecting the optical performance such as lens surface shape, thickness error, decentration, and refractive index.

Note that the screen 10 rotates several times per second in order to avoid a speckle pattern peculiar to a laser.
The interferometer 4 will be further described.

  The light from the laser 11 passes through the variable ND filter 43 and is then expanded in diameter by the beam expander 12. As the convex lens 13 constituting the beam expander 12, an objective lens of a microscope or the like is often used. The narrowed beam passes through the pinhole 44 and enters the collimator 14 composed of a cemented lens whose aberration has been sufficiently corrected as an ideal spherical wave, and becomes a parallel wave and a plane wave whose phases are aligned in the traveling direction.

  The light passing through the aperture stop 15 after the beam expander 12 is divided into the two optical paths R and S by the beam splitter 16 as described above, and is reflected by the mirrors 17 and 18, respectively. The mirror 18 in one optical path S has a piezo element 19, and by scanning the interference fringes by slightly changing the distance of the optical path S, the difference between the wavefronts described above is a value including the sign, It can be obtained from a plurality of interference fringes having different phases.

As shown in FIG. 2, the reference lens 6 and the test lens 7 are placed on a lens holder 20 having a predetermined structure and placed on a stage 21 disposed in the optical path.
A height H from the reference surface of the stage 21 to the reference lens 6 (or the test lens 7) is set to a predetermined height. The lens holder 20 is pressure-bonded to the stage 21 with a spring or the like. Further, the reference lens 6 is fixed to the lens holder 20 with an adhesive or a leaf spring.

  Further, the condensing lenses 22 and 23 arranged after the reference lens 6 and the test lens 7 are fixed, and the light beams that have passed through these are combined into one by the beam splitter 24 and are formed on the screen 10 as interference fringes. make.

  As the condensing lenses 22 and 23, for example, a lens composed of a plurality of convex lenses and a concave meniscus lens may be used. Plano-concave lenses 34 and 35 are arranged on the imaging system (imager 29) side of the condenser lenses 22 and 23.

  The screen 10 can be adjusted in the direction of the arrow along the optical axis, adjusts the projection diameter of the light beam that has passed through the reference lens 6 and the lens 7 to be tested, and reduces the distortion on the projection surface for parallel light. Used to install on.

  The light that has passed through the two optical paths R and S are combined together by the beam splitter 24, and an interference fringe is formed on the screen 10 by the imaging lens 25. The imaging lens 25 is fixed to the frame of the interferometer 4.

  The interference fringes formed on the screen 10 are enlarged by the auxiliary close-up lens 27, and behind the TV zoom lens 28, the interference fringes can be enlarged and reduced to an appropriate size so that the TV camera can be adjusted. An image is formed on the imager 29.

The auxiliary close-up lens 27, the TV zoom lens 27, and the screen 10 are integrally movable in the optical axis direction.
The signal from the imager 29 is input to the fringe analyzer 5, where the interference fringes are analyzed, the wavefront aberration of the lens 7 to be examined is clarified, and pass / fail is determined (S300 in the flowchart described later). reference).

  Further, the interference fringes can be observed on the television monitor 30 in real time. Therefore, the television monitor 30 takes in the NTSC signal from the TV camera as it is. The color display 31 displays the result after image processing.

Next, an operation procedure for starting the measurement of the aberration amount of the lens 7 to be examined will be described.
The reference lens 6 and the test lens 7 are placed on the stage 21 together with the lens holder 20 (see FIG. 2), the lens holder 20 on which the test lens 7 is placed is rotated, and the test lens 7, the reference lens 6 and Alignment is performed so that the shape of the interference fringes generated by the interference of the lens rotates without changing the shape with the rotation of the test lens 7.

  Next, phase data (data corresponding to the difference between the wavefronts of the reference lens 6 and the test lens 7) is obtained from a plurality of interference fringes obtained by performing a fringe scan by the fine movement of the mirror 18, whereby the reference lens 6 is scanned. The optical performance is inspected by measuring the wavefront aberration of the lens 7 to be examined.

  Subsequently, the defect of the optical surface of the test lens 7 is measured. Here, the term “defect” is used as a concept including scratches, blisters, spiders, adhesion of foreign matter, bubbles present in a medium such as resin or glass, and the like. In addition, these defects include those that block light and those that do not block light. In this embodiment, it is possible to create a state in which any defect can be observed.

In this way, the optical performance of the lens 7 to be measured and the measurement of defects can be simultaneously performed by one lens measuring device 1.
FIG. 3 is a diagram showing the interference fringes 50 projected on the screen 10 by the transmitted wavefront measurement of the lens 7 to be examined using the lens measuring device 1.

  In the drawing, the screen 10 shows a large foreign object 51 attached to the optical surface of the lens 7 to be examined together with the interference fringes 50. However, in this state, the image of the foreign object 51 is blurred due to the stripe pattern and is unclear. There are other small foreign objects on the optical surface of the lens 7 to be examined, but it is difficult to identify them in this image. In addition, since the interfering image includes information on the optical path R, it is difficult to separate the defect image generated in the optical path S or the defective image generated in the optical path R. .

  That is, after measuring the aberration amount of the lens 7 to be measured with the interference fringe 50 using the lens measuring device 1, it can be seen that it is difficult to further identify the foreign matter 51 and the like reflected together with the interference fringe 50.

FIG. 4 is a diagram showing an image projected on the screen 10 with one of the two optical paths R and S (for example, the optical path R) closed using the lens measuring device 1.
In this case, since interference between the light beams from the two optical paths R and S does not occur, the interference fringes 50 are not formed on the screen 10, and the foreign matter identification ability is higher than in the state of FIG. Although the generated defect image can be removed, it is difficult to recognize a smaller foreign object from the image.

  That is, after measuring the aberration amount of the test lens 7 by the interference fringe 50 using the lens measuring device 1, even if one optical path is closed and an image of the optical surface of the test lens 7 is formed on the screen 10, There is a need to further measure detailed defects in the lens 7.

Therefore, in this embodiment, the defect of the test lens 7 is measured simultaneously (continuously) with the measurement of the aberration amount of the test lens 7.
FIG. 5 shows an image of a defect of the lens 7 to be tested formed on the screen 10 using the measurement method of the present embodiment.

According to the figure, not only large foreign objects 51 can be identified, but also small foreign objects 52 can be clearly identified on the screen.
Next, based on FIG. 1, FIG. 6, and FIG. 7, a method for measuring a defect of the lens 7 to be measured using the lens measuring device 1 will be described.

First, the shutter 32 and the shutter 33 arranged in the middle of the two optical paths R and S are closed, or the laser light is shielded by the variable ND filter 43.
The defect measurement of the test lens 7 is performed in the same posture as the measurement posture of the test lens 7 in the transmitted wavefront measurement for measuring the aberration amount. That is, the test lens 7 is placed on the stage 21 together with the lens holder 20 without changing the test lens 7 (see FIG. 2).

  As described above, the test lens 7 once set in the lens measuring instrument 1 for measuring the aberration amount of the test lens 7 is subjected to the defect measurement in the same state, thereby reducing the man-hours and measuring. The accuracy can be improved.

As a setting change point of the optical system, in the mode for measuring the aberration amount of the lens 7 to be tested, the purpose is to project the light transmitted through the lens 7 on the screen. As shown in FIG. 6, the object point (the light source of the focusing lens system) becomes the lens 7 itself. The imaging optical system forms an image on the screen 10.

  In order to change to the imaging optical system, in this embodiment, a diaphragm 66 that is not used in the mode for measuring the amount of aberration is used immediately after the test lens 7. The diaphragm 66 is narrowed as shown in FIG. 6 so that the optical surface of the test lens 7 is imaged at the position of the screen 10.

The diaphragm 66 is maintained in an open state when measuring the amount of aberration, and is used by appropriately narrowing down when measuring defects.
Further, the observation object of the defect is the optical surfaces on both the front and back sides of the lens 7 to be tested and the inside of the medium between them. The position of the defect is determined by moving the screen 10 in the optical axis direction and focusing on the defect. And by detecting the focus position.

  Naturally, by changing (squeezing) the diameter of the stop, the depth of field (the in-focus range) can be increased, and both surfaces of the test lens 7 can be observed simultaneously. Of course, by changing the position of the stop in the optical axis direction, changing the focus position, correcting the curvature of field of the image plane, which occurs because the test lens 7 serving as an object point is not flat, etc. You can go.

  Next, as shown in FIG. 7, the test lens 7 is irradiated with illumination light 53 different from the laser 11 used for measuring the aberration amount. Here, the illumination light 53 is irradiated while being inclined with respect to the optical axis 40 from a direction different from the optical axis 40 of the lens 7 to be examined. In the present embodiment, as the illumination light 53, light obtained from the light emitted from the LED 54 via the condenser lens 55 is used. The illumination light may be appropriately used for diffused light, condensed light, or surface emitting illumination.

Further, the illumination light 53 for measuring the defect may be irradiated from both the front and back sides of the optical surface of the lens 7 to be tested, or the illumination light 53 may be applied from one side of the optical surface. Good.
When a light beam parallel to the optical axis 40 is irradiated in the same way as when measuring aberration (when measuring the transmitted wavefront) (varies depending on the shape of the lens being measured), the bright spot of the illumination light is at the center of the observed image. Is often reflected, and areas other than the bright spot visible in the center are dark fields.

  Further, a light source that emits light as a surface, for example, a surface light emitting panel 67 may be installed like a backlight on the side of the test lens 7 where the light from the laser 11 is incident. From the imager 29 side, the range of the angle θ in FIG. 7 can be seen through the back side. Thus, if the range that can be observed from the imager 29 through the test lens 7 is brightened, observation in a bright field state is possible, and in this case, it is possible to detect a defect that blocks light.

  When the illumination light 53 is irradiated to the lens 7 to be inspected from an angle outside the visual field range of the imaging system (imager 29) by tilting the light beam with respect to the optical axis 40, observation in a dark field is possible. I can do it. This allows detection of defects that do not block light. In this case, the contrast of the defect is improved by blackening or shading the area reflected on the back side through the demonstration lens 7 (area where the surface emitting panel 67 is installed).

  Further, the defect of the test lens 7 can be measured by rotating the test lens 7 together with the lens holder 20 (see FIG. 2), and a plurality of obtained images can be synthesized and evaluated. Thereby, when the ghost and flare of illumination light move to a screen, the image removed without moving illumination light can be obtained.

If it is difficult to focus on a lens with a large thickness or a lens with a strong curve, capture multiple images or only the image of the edge while moving the image plane to generate a focused image. You can also.

  Note that the screen 10 was used to project the interference fringes when measuring the aberration of the lens 7 to be measured (when measuring the transmitted wavefront). The hollow imaging surface may be retracted from the axis and directly relayed by the imaging optical system to form an image on the imager 29. Alternatively, the imager 29 (photographing system) may be arranged directly on the projection surface of the screen 10.

That is, the setting of the observation optical system from the lens 7 to be examined to the screen 10 and the imager 29 is changed as necessary for increasing the resolution.
Next, the manufacturing process of the optical element according to the present embodiment will be described with reference to the flowchart of FIG.

S100 to S900 are diagrams showing the measurement process of the aberration amount of the lens 7 to be measured and the measurement process of the defect from the manufacturing process of the optical element.
The manufacturing process of this embodiment will be briefly described. In step 100 (hereinafter referred to as “S100”), the test lens 7 is molded by a lens molding machine, and the test lens 7 as a measurement target is molded here.

  Next, in S200, the molded test lens 7 is attached to the lens measuring machine (lens comprehensive inspection machine) 1, and further, an interference fringe is generated in S300, and the aberration amount of the test lens 7 is determined from the interference fringe. Measure (transmitted wavefront measurement).

As a result, if the aberration amount of the lens 7 to be tested is outside the preset standard value, it is discarded as a defective product (S400).
If the aberration amount of the test lens 7 is within a preset standard value, the presence or absence of a lens defect is measured in S500.

  As a result, if there is no defect in the lens or if it is within the standard value, the measurement ends in S600 and the process returns to S100. If there is a lens defect, the lens molding machine is corrected in S700.

Hereinafter, the detail of each process of S100-S900 is demonstrated.
(Step of S100)
S100 is a molding process of the test lens 7 by the molding machine.

  FIG. 9 shows a cross-sectional view of a mold block 61 disposed in a molding machine (not shown). Normally, the mold block 61 is placed in an inert gas atmosphere and press molding is performed, but the illustration thereof is omitted here.

A molding material 62 is accommodated in the mold block 61. This molding material 62 is press-molded by an air cylinder (not shown), and the test lens 7 is molded.
The mold block 61 has an upper mold 63, a lower mold 64, and a sleeve 65. The upper mold 63 and the lower mold 64 are inserted from both ends of the sleeve 65 so that the molding surfaces 63a and 64a face each other inside the sleeve 65.

The upper mold 63 is slidable in the axial direction of the sleeve 65. The optical material 62 is disposed between the molding surface 63 a of the upper mold 63 and the molding surface 64 a of the lower mold 64.
(Step S200)
S200 is a process of mounting the test lens 7 on the lens measuring device 1, and as described above, the test lens 7 is mounted on the lens holder 20 (not shown).
(Steps S300 and S400)
S300 is a step of checking interference fringes, and since it has been described above, the description thereof is omitted. Here, as a result of checking the interference fringes, when the aberration amount of the lens 7 to be tested is out of the standard, the process proceeds to S400 and the lens 7 to be tested is discarded.
(Steps S500 and S600)
In S500, the defect of the test lens 7 is measured for the test lens 7 whose aberration amount is within the standard.

As a result, if there is no defect or it is within the standard, in S600, the measurement is finished with the test lens 7 as a non-defective product, and then the process returns to the first step S100 to measure the next test lens 7. I do.
(Steps S700 to S900)
In S700, when it is determined that there is a defect, whether there is an abnormality that causes the defect to be generated in the molding machine by feeding back the defect information to the molding machine side, and whether the abnormality can be corrected or not. Determine. As a result, for example, when foreign matter adheres to the front or back optical surface of the lens 7 to be examined, or there is a scratch, the molding surface 63a ( Alternatively, it is checked whether or not foreign matter has adhered to the molding surface 64a) of the lower mold 64.

  This is because if there is a cause such as adhesion of foreign matter, it may be corrected by cleaning the mold surface. In such a case, the process proceeds to S800, and in this step, the molding surface 63a of the upper mold 63 (or the molding surface 64a of the lower mold 64) is subjected to maintenance such as cleaning. Then, it progresses to S600 and returns.

  On the other hand, as a result of feedback of defect information to the molding machine side, there may be a case where significant improvement of the molding machine is required. In this case, the process proceeds to S900, the molding is stopped, and necessary measures are taken.

  According to the present embodiment, the defect measuring function is added to the lens measuring device 1 that measures the transmitted wavefront of the lens 7 to be measured, so that the transmitted wavefront of the optical element can be measured and the optical function surface defect can be achieved with a single device. Can be measured simultaneously.

  That is, until now, after measuring the transmitted wavefront of the test lens 7 (measuring the amount of aberration), if necessary, the test lens 7 is moved and the defect is measured by a dedicated visual inspection machine or the like. However, according to the present embodiment, the measurement of the transmitted wavefront of the optical element and the measurement of the defect of the optical function surface can be performed simultaneously by setting the lens 7 to be measured once in the lens measuring machine 1. it can.

  According to the present embodiment, it is possible to measure a defect in addition to the measurement of the transmitted wavefront of the lens 7 to be measured with the single lens measuring device 1, and increase the performance evaluation items of the lens. Can do.

It is a figure which shows the whole structure of the lens measuring machine used for this invention method. It is a figure which shows the attachment structure of a reference | standard lens and a to-be-tested lens. It is a figure which shows the interference fringe projected on the screen by the transmitted wavefront measurement of a lens using a lens measuring device. It is a figure which closes one optical path of a lens measuring machine, and shows the image projected on the screen. An image of an optical surface of a test lens is shown using the measurement method of the present embodiment. It is an optical system image at the time of the defect measurement of a to-be-tested lens. It is a figure which shows the state which inclined and irradiated the illumination light from the direction different from an optical axis. It is a figure which shows the flowchart of the manufacturing process of the optical element in this embodiment. It is sectional drawing of a metal mold block.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens measuring machine 4 Interferometer 5 Stripe analysis apparatus 6 Reference lens 7 Test lens 10 Screen 11 Laser 12 Beam expander 13 Convex lens 14 Collimator 15 Brightness stop 16 Beam splitter 17 Mirror 18 Mirror 19 Piezo element 20 Lens holder 21 Stage 22 Condensing lens 23 Condensing lens 24 Beam splitter 25 Imaging lens 27 Auxiliary close-up lens 28 TV zoom lens 29 Imager 30 TV monitor 31 Color display 32 Shutter 33 Shutter 34 Plano-concave lens 35 Plano-concave lens 40 Optical axis 43 Variable ND filter 44 Pin Hall 50 Interference fringe 51 Large foreign object 52 Small foreign object 53 Illumination light 54 LED
55 Condensing lens 61 Mold block 62 Molding material 63 Upper mold 63a Molding surface 64 Lower mold 64a Molding surface 65 Sleeve 66 Diaphragm 67 Surface emitting panel

Claims (8)

On the apparatus for measuring the aberration amount of the test lens from the generated interference fringes by causing the light beam transmitted through the reference lens as the comparison target to interfere with the light beam transmitted through the test lens as the measurement target. the defect is measured,
Measurement of the defect of the test lens,
The same as the measurement posture of the lens to be measured at the time of transmission wavefront measurement for measuring the amount of aberration ,
And without performing interference between the light beam transmitted through the reference lens and the light beam transmitted through the test lens,
And by changing the setting of the optical system from the lens to be examined to the projection surface and the imaging system,
In addition, it is performed by adding a diaphragm to the observation optical system.
The method of measuring an optical element according to claim 1. Measurements of an optical element according to claim 1, wherein the measuring of the defects of the lens, and performing by shielding the light beam transmitted through the reference lens. The optical element measurement method according to claim 1, wherein the measurement of the defect of the test lens is performed by irradiating the test lens with a light beam different from the measurement of the aberration amount. The optical element measurement method according to claim 3 , wherein the measurement of the defect of the lens to be measured is performed by irradiating a light beam different from the measurement of the aberration amount from a direction different from the optical axis. The optical element measurement method according to claim 3 or 4 , wherein the measurement of the defect of the test lens is performed by irradiating a light beam different from the measurement of the aberration amount from both surfaces of the test lens. . Measurements of an optical element according to claim 1 or 3 measurements of defects in the lens under test, and performing said by rotating the test lens. The measurement of the defects of the lens is performed by rotating the test lens, the measurement method of the optical element according to claim 1 or 3, characterized in that evaluation by synthesizing a plurality of images obtained . A molding process for molding a lens to be measured as a measurement object;
A defect in the test lens is detected on an apparatus for measuring the amount of aberration of the test lens from interference fringes generated by causing the light beam transmitted through the reference lens as a comparison target to interfere with the light beam transmitted through the test lens. a measurement step of claim 1 to 7 to be measured,
Whether to continue molding of the test lens based on the measurement result in the measurement process or to feed back to the molding process the maintenance timing of the mold and molding apparatus used for molding,
A method for manufacturing an optical element.